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Date:   Mon, 25 Oct 2021 17:05:03 -0400
From:   Steven Rostedt <rostedt@goodmis.org>
To:     Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc:     Yafang Shao <laoar.shao@gmail.com>,
        Andrew Morton <akpm@linux-foundation.org>,
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Subject: Re: [PATCH v6 00/12] extend task comm from 16 to 24
Message-ID: <20211025170503.59830a43@gandalf.local.home>
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On Mon, 25 Oct 2021 11:10:09 -0700
Alexei Starovoitov <alexei.starovoitov@gmail.com> wrote:

> It looks like a churn that doesn't really address the problem.
> If we were to allow long names then make it into a pointer and use 16 byte
> as an optimized storage for short names. Any longer name would be a pointer.
> In other words make it similar to dentry->d_iname.

That would be quite a bigger undertaking too, as it is assumed throughout
the kernel that the task->comm is TASK_COMM_LEN and is nul terminated. And
most locations that save the comm simply use a fixed size string of
TASK_COMM_LEN. Not saying its not feasible, but it would require a lot more
analysis of the impact by changing such a fundamental part of task struct
from a static to something requiring allocation.

Unless you are suggesting that we truncate like normal the 16 byte names
(to a max of 15 characters), and add a way to hold the entire name for
those locations that understand it.

-- Steve